熔喷非织造用聚(3-羟基丁酸-co-3-羟基戊酸共聚酯)/聚乳酸双组分生物降解材料的可纺性能

采用熔融共混法制备了质量比为100/0、75/25、50/50、25/75、0/100的熔喷非织造用PHBV/PLA共混材料，分别采用热重分析法（TG）、熔融指数法（MFI）、热台偏光镜法（POM）和毛细管流变法对共混材料的可纺性能进行了研究，并对其初生纤维的纺丝性能给予了初步评价。研究表明：PHBV的热稳定性差、加工窗口窄且熔体流动性差，PHBV/PLA共混材料的热稳定性和熔体流动性明显改善；PHBV结晶速率快, PLA对PHBV的结晶具有稀释作用；PHBV/PLA共混物为典型的切力变稀型流体，PHBV对温度和剪切速率变化敏感度高，PHBV/PLA共混材料的表观粘度随着PLA含量的提高而有所增大，但均小于纯PLA；PHBV纤维发粘现象严重，纺丝困难，随着共混材料中PLA含量的提高，纺丝性能提高，初生纤维表面变得光滑。

Study on spinnability of biodegradable poly(3-hydroxybutyrate-co-3-hydroxyvalerate)/poly(lactic acid) blends for melt-blown nonwovens

Poly ( 3-hydroxybutyrate-co-3-hydroxyvalerate ) ( PHBV ) and poly ( lactic acid ) ( PLA ) blends for melt-blown nonwovens with different ratios ( 100/0 , 75/25 , 50/50 , 25/75 , 0/100 ) were prepared by melt mixing. The thermal properties, melt flowing indexes, crystallization and rheological behaviors of PHBV/PLA blends were investigated, and its as-spun fiber was also prepared to evaluate the spinnability of the blends. The results showed that pure PHBV had poor thermal stability, narrow processing window and low melt flowing rate, and blended with PLA improved the thermal stability and melt fluidity of PHBV;pure PHBV also had fast crystallization rate with nucleating agent and PLA had a dilution effect on the crystallization of PHBV; PHBV had high sensitivity to the temperature and shear rate changes, PHBV/PLA blends had mixing characteristic of shear thinned liquid and the apparent viscosity of blends increased with the increasing of the content of PLA but was less than pure PLA; and PHBV had poor spinnability with serious sticky situation and low drawing ratio of as-spun fiber, but it could be improved by the blending of PLA and the surface also became smoother.